Vehicle Braking System Comprising A Parking Brake Indicator Device And Vehicle Provided With Such A System

ABSTRACT

A braking system for a vehicle includes an indicator device provided to reliably indicate a state of a parking brake of the system, while being simple, convenient, and economical. The system includes a body that delimits a service brake pressure chamber and/or a parking brake pressure chamber, a parking brake movable relative to the body, an unlocking part for unlocking the parking brake connected to the parking brake pressure chamber and accessible from outside the body, and a parking brake indicator device. The indicator device is configured to receive a position of the unlocking part via a state pipe and an indicator of supply and/or the venting of the service brake pressure chamber and/or of the parking brake pressure chamber. This information is processed in to detect and indicate an engaged state or a disengaged state of the parking brake.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry of, and claims priority to,International Patent Application No. PCT/FR2020/050416 (filed 2 Mar.2020), which claims priority to French Patent Application No. 1902196(filed 4 Mar. 2019). The entire contents of these applications areincorporated herein by reference.

BACKGROUND Technical Field

The invention concerns the field of rail vehicle brakes. Moreparticularly, it concerns a braking system for a rail vehicle,comprising an indicator device provided to indicate a state of a parkingbrake of said braking system. It also concerns the rail vehiclescomprising such a system.

Discussion Of Art

Rail vehicles are generally equipped with service brake cylinderscomprising a piston movable under the effect of a fluid under pressure,the movement of that piston driving a braking action such as theclamping of a disk brake between two linings, or the direct pressure ofa block against a vehicle wheel.

These brake cylinders also generally comprise a parking or emergencyactuator which is actuated in case of pressure loss of the fluid underpressure and/or in case of intentional venting (or draining) or leakageof the pneumatic system. This actuator, also termed parking brake, makesit possible to provide braking by virtue of the load of one or moresprings substituting for the load of the fluid. Once this parking brakehas been activated, the brake remains continuously engaged.

A rail vehicle braking system is known from European patent applicationEP 2 154 040 which is provided in particular with a parking brakeactuator coupled to a rail vehicle service brake cylinder. Such aparking brake makes it possible to provide braking by virtue of the loadof a spring substituting for the load of the fluid.

From European patent application EP 2 826 684 there is also known a railvehicle braking system provided in particular with a parking brakedisposed in the service brake cylinder and comprising a blocking deviceconfigured to act on a rod of the brake piston of the service brake, andan actuating device of the blocking device. The blocking device and theactuating device are configured such that, when the braking piston is ina service braking position and the parking brake is in workingconfiguration, the actuating device acts on said blocking device untilthe latter immobilizes the piston rod so as to block the braking pistonin its service braking position, and when the parking brake is inresting configuration, the actuating device acts on the blocking deviceuntil the latter releases the piston rod so as to unblock the brakingpiston from its service braking position.

These braking systems are mounted on the rail vehicle, to be in contactwith the brake disks or the wheels. In particular, they may bemechanically connected to the bogies, or to the axles fastened to thebogies, or on other devices like the drive motor or the gearbox alsomounted on the bogies.

BRIEF SUMMARY

One or more embodiments of the inventive subject matter concern abraking system for a vehicle (e.g., a rail vehicle), where the brakingsystem comprises an indicator device provided to reliably indicate astate of a parking brake of the system, while being simple, convenient,and economical.

According to a first aspect, the invention relates to a rail vehiclebraking system comprising a body delimiting a service brake pressurechamber and/or a parking brake pressure chamber, a parking brake movablerelative to the body, an unlocking part for unlocking the parking brakeconnected to the parking brake pressure chamber and accessible fromoutside the body, and a parking brake indicator device. The indicatordevice is configured to receive a first item of information representinga position of the unlocking part via a state pipe configured to beconnected to the unlocking part. The indicator device also is configuredto receive at least one second item of information representing thesupply and/or the venting of the service brake pressure chamber and/orof the parking brake pressure chamber, via at least one other state pipeconfigured to be connected to a service brake pipe and/or to a parkingbrake. The first item of information is processed in combination withthe at least one second item of information so as to detect and indicatean engaged state or a disengaged state of the parking brake.

The indicator device of the braking system is thus configured to detectand indicate the state in which the parking brake of the braking systemis in taking into account not only the position of the unlocking partfor unlocking the parking brake but also the state of the service brakepressure chamber and/or the state of the parking brake pressure chamber.

Taking into consideration the state of the service brake pressurechamber and/or the state of the parking brake pressure chamber may becarried out by receiving an item of information directly concerning thepressure in these chambers or else concerning settings for applicationof the parking brake and/or of the service brake.

It will be noted that the rail vehicle braking system may comprise abraking linkage configured to act on at least one brake of a railvehicle having a lining or a block. The braking system also can includea service brake comprising a braking piston movable relative to the bodyto act on the braking linkage and delimiting (with the body) the servicebrake pressure chamber. The service brake pressure chamber is configuredto be supplied by a first source of pneumatic pressure agent to placethe braking piston in a service braking position. The parking brake maybe configured to act on the braking piston of the service brake andtakes a working configuration and a resting configuration. The parkingbrake may comprise a blocking device which is movable relative to thebody to act on the braking piston and can take a first position and asecond position in which the blocking device is configured to immobilizethe braking piston in service braking position (the parking brake thenbeing in working configuration). The parking brake may comprise anactuating device which is movable relative to the body and which has alocking position in which the actuating device is configured to hold theblocking device in its second position. The rail vehicle braking systemmay be configured to supply the service brake pressure chamber withanother pneumatic pressure agent of which the value of the pressure isdetermined, so as to apply a determined braking force when the parkingbrake is in working configuration.

Features according to the inventive subject matter that are preferred,simple, convenient, and economical are presented below.

The indicator device is configured to receive an item of informationrepresenting the supply of the service brake pressure chamber by apneumatic pressure agent, via a second state pipe which is connected toa parking brake setting pipe, and an item of information representingthe supply of the service brake pressure chamber by another pneumaticpressure agent, via a third state pipe which is connected to a servicebrake pipe.

The unlocking part is coupled to a switch of the indicator device whichis mechanically connected to that part and has a first position and asecond position.

The indicator device comprises a first parking contactor devicemechanically connected the unlocking part, a second parking contactordevice which is connected via the first state pipe to the first parkingcontactor device, a third parking contactor device, and a fourth parkingcontactor device which are each connected via the second state pipe tothe parking brake setting pipe. The third and fourth parking contactordevices are respectively connected to the second parking contactordevice and to respective visual parking indication devices of theindicator device.

The second parking contactor device may be electrically supplied via anelectrical source.

The third and fourth respective parking contactor devices may be formedby pressure switches or sensors.

The parking brake is in an engaged state and the visual parkingindication device is on when the second parking contactor devicereceives an item of information from the first state pipe (according towhich the unlocking part is in an unlocking position) and the fourthparking contactor device receives an item of information from the secondstate pipe (according to which there is a parking brake setting in theparking brake pipe corresponding to a setting for application of theparking brake).

The parking brake is in a disengaged state and the visual parkingindication device is on when the second parking contactor devicereceives an item of information from the first state pipe (according towhich the unlocking part is in an unlocking position) and the thirdparking contactor device receives an item of information from the secondstate pipe (according to which the parking brake setting has a nullvalue in the parking brake pipe).

The indicator device comprises a first parking contactor devicemechanically connected to the unlocking part, a second parking contactordevice connected via a first state pipe to the first parking contactordevice, and a third contactor device connected to another state pipeitself joined either to a supply pipe of the parking brake, or to asetting pipe of the parking brake.

The parking brake is in the engaged state and a visual parkingindication device is then turned on when the second parking contactordevice receives an item of information from the state pipe (according towhich the unlocking part is in a locking position) and the third parkingcontactor device receives an item of information from the other statepipe (according to which there is a parking brake setting and/or whenthe parking brake pressure chamber of the system is not supplied,corresponding to a setting for application of the parking brake).

The parking brake is in the disengaged state and the other of the visualparking indication devices is then turned on, whatever the item ofinformation received by the third parking contactor device when thesecond parking contactor device receives an item of information from thestate pipe (according to which the unlocking part is in an unlockingposition).

According to a second aspect, the inventive subject matter also relatesto a vehicle such as a rail vehicle with brakes having at least onelining or at least one block. The vehicle includes at least one brakingsystem as described above and configured to act on the at least onelining or on the at least one block of the rail vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure of the inventive subject matter will now be continuedwith the description of embodiments, given below by way of illustrativeand non-limiting examples, with reference to the accompanying drawings.

FIG. 1 is a diagrammatic and partial illustration of a braking systemprovided in particular with a service brake, a parking brake, and acontrol and actuation unit.

FIG. 2 represents diagrammatically and in more detail the control andactuation unit illustrated in FIG. 1 and a conveyance network of pipesof the system, which is connected to that unit.

FIG. 3 shows in more detail part of the control and actuation unitillustrated in FIG. 2 (e.g., a parking brake and/or service brakeindicator device of the braking system).

FIG. 4 shows the part of the indicator device illustrated in FIG. 3 andwhich is in particular provided to indicate a state of the parkingbrake.

FIG. 5 illustrates a first configuration of the parking brake.

FIG. 6 illustrates a second configuration of the parking brake.

FIG. 7 illustrates a third configuration of the parking brake.

FIG. 8 shows the part of the indicator device illustrated in FIG. 3 andwhich is in particular provided to indicate a state of the servicebrake.

FIG. 9 shows a first variant embodiment of the part of the indicatordevice provided to indicate a state of the service brake.

FIG. 10 shows a second variant embodiment of the part of the indicatordevice provided to indicate a state of the service brake.

FIG. 11 shows a third variant embodiment of the part of the indicatordevice provided to indicate a state of the service brake.

DETAILED DESCRIPTION

FIG. 1 diagrammatically represents a braking system 1 for a rail vehiclewith a brake having linings or blocks.

This is a rail vehicle braking system structurally of the type describedin European patent application EP 2 826 684.

The rail vehicle braking system 1 comprises a body 2 here forming acylinder of a service brake 6 and a parking brake 7, a control andactuation unit 3 configured to manage the operation of the service brake6 and of the parking brake 7, a conveyance network of pneumatic pipesthat is connected to the body 2 and to the control and actuation unit 3,a braking linkage 4 mechanically linked to the body 2, and a brake 5with linings on which the braking linkage 4 is configured to act.

The body 2 here has the form of a generally closed envelope.

The service brake 6 comprises a service brake piston 8 movable relativeto the body 2 in a first axial direction, and a thrust rod 9 alsomovable relative to the body 2 in a second axial direction perpendicularto the first axial direction.

Together with the body 2, the braking piston 8 delimits a service brakepressure chamber 13.

The braking piston 8 has two sides respectively a first side 17configured to act on the braking linkage 4 via the thrust rod 9 and asecond side 18 which is an opposite side to the first side 17 and whichis turned towards the service brake pressure chamber 13.

The service brake 6 further comprises a notched rod 21 fastened to thesecond side 18 of the braking piston 8. This notched rod 21 extendslongitudinally in the first axial direction.

The braking piston 8 is configured to move in the body 2 whilemaintaining the service brake pressure chamber 13 relatively fluid-tightthanks to a membrane 14, for example formed by a seal, disposed betweenthat braking piston 8 and inside edges of the body 2.

The service brake 6 may further comprise a wedge part 10 fastened to thefirst side 17 of the braking piston 8.

This wedge part 10 may have a triangular section and be configured tocooperate with a set of rolling bearing stops 11, of which one of therolling bearing stops may be linked to the body 2 while the other of therolling bearing stops may be linked to the thrust rod 9.

This thrust rod 9 may be provided with a wear adjuster configured tocompensate for the wear of the linings of the brake 5 in order to avoidreduction of the braking force by excessive play (further to wear of thelinings).

The service brake 6 may comprise a spring 12 disposed around the thrustrod 9, between the rolling bearing stop which is linked to the latterand an inside edge of the body 2. This spring 12 is configured to returnthe stop which is linked to the thrust rod 9 against the wedge part 10.

The service brake 6 may comprise a first aperture 15 formed in the body2 and configured to enable the movement of the thrust rod 9 through thatfirst aperture 15.

The service brake 6 may comprise a second aperture 16 formed in the body2 and opening into the service brake pressure chamber 13.

The service brake pressure chamber 13 is connected here by a firstsupply pipe 72 of the conveyance network of pneumatic pipes, moregenerally called brake pipe, which pipe is connected at the location ofthat second aperture 16, to a source of supply of pneumatic pressureagents 73 (visible in FIG. 2).

The body 2 comprises a cavity 27 situated against the service brakepressure chamber 13 and in which is disposed the parking brake 7.

The parking brake 7 comprises a blocking device formed by a blockingfinger 20 movable relative to the body 2 and extending in the secondaxial direction.

The parking brake 7 comprises a holding piston 23 movable relative tothe body 2 and with the latter delimiting a parking brake pressurechamber 25.

This holding piston 23 has two sides, respectively a first side 31 onwhich is attached the blocking finger 20 and which is turned towards theparking brake pressure chamber 25, and a second side 32 which is anopposite side to the first side.

The parking brake 7 comprises a spring member 24 disposed between thebody 2 and the second side 32 of the holding piston 23. This springmember 24 is configured to act on that holding piston 23 and thereforeon the blocking finger 20.

The holding piston 23 and the spring member 24 may form a movableactuating device of the parking brake 7.

The holding piston 23 is configured to move in the body 2 whilemaintaining the parking brake pressure chamber 25 relatively fluid-tightthanks to a membrane disposed between that holding piston 23 and theinside edges of the body 2.

The parking brake 7 comprises a third aperture (not shown) formed in thebody 2 and opening both into the parking brake pressure chamber 25 andinto the service brake pressure chamber 13, which third aperture isconfigured to enable the movement of the blocking finger 20 through thatthird aperture.

The relative sealing between the parking brake pressure chamber 25 andthe service brake pressure chamber 13 is ensured by the presence of aseal 33 disposed at the interface between that third aperture and theblocking finger 20.

The parking brake 7 comprises a fourth aperture 28 formed in the body 2and opening into the parking brake pressure chamber 25.

The parking brake pressure chamber 25 may be connected here by a secondsupply pipe 71 of the conveyance network of pneumatic pipes, also calledparking brake pipe, which is connected at the location of that fourthaperture 28, to the source of supply of pneumatic pressure agents 73(visible in FIG. 2) via the unit 3.

The parking brake 7 comprises an unlocking part 29 to deactivate theparking brake 7.

The unlocking part 29 may for example be attached on the second side 32of the holding piston 23 and open to the outside of the body 2 through afifth aperture (not shown) provided in that body 2 and opening into thecavity 27.

The unlocking part 29 is accessible to be manipulated from outside thebody 2 if required.

As explained later, the unlocking part 29 is connected to an indicatordevice provided to indicate a state of the parking brake 7 and/or astate of the service brake 6.

In particular, the unlocking part 29 may be coupled to a switchmechanically connected to that part 29 and having a first position and asecond position selected according to the position of the unlocking part29.

The service brake 6 is disposed in the body 2 and is configured to acton the brake 5 via the braking linkage 4.

This brake 5 may comprise a brake disk 35 (here viewed from above)mounted for example on a rail vehicle axle 36, or directly on the wheelto brake.

This brake 5 may comprise two shoes 37 each provided with a lining 38configured to be applied in contact with the disk 35 to reduce itsrotational speed and therefore that of the wheel to brake, as well as afastening eye 39 provided at the remote opposite location to the surfaceof the lining 38 that is configured to be applied to the disk brake 35.

The braking linkage 4 may comprise two or four deformable levers 40 eachprovided with an upper portion and a lower portion which are attached toeach other. Only two levers are illustrated here and, in the case of thelinkage having four levers, they may be attached in pairs or as avariant be independent from each other.

Each portion of the levers 40 may be jointed to a central connector 41via two pivots 42.

The lower portion of each deformable lever 40 may be linked to one ofthe shoes 37 via its fastening eye 39.

The upper portion of each deformable lever 40 may be linked to arespective joint 44, 45.

The braking linkage 4 may receive the body 2 between the upper portionsof the deformable levers 40, at the location of the joints 44 and 45.

The body 2 may be rotatably mounted on the joint 44 which is attached toan end of the thrust rod 9 whereas it may have a fixed mounting to thejoint 45, which is directly attached to that body 2.

The braking linkage 4 may comprise a fastening lug 43 joined to thecentral connector 41 for the mounting of that braking linkage 4 on therail vehicle; in order for the brake shoes 37 to be situated onrespective opposite sides of the brake disk 35 (or of the wheel of therail vehicle).

The coming towards each other of the joints 44 and 45 may enable theshoes 37 to move apart from each other and that conversely, theseparation of those joints 44 and 45 may enable the shoes 37 to be toclamped onto the brake disk 35 (or onto the rail vehicle wheel).

The control and actuation unit 3 is connected to the service brakepressure chamber 13 via the first supply pipe 72 to which it isconnected.

This unit 3 is connected to the parking brake pressure chamber 25 viathe second supply pipe 71 to which it is connected.

This unit 3 is supplied with pneumatic agents by a main pipe 70 whichpasses generally along the rail vehicle.

The unit 3 comprises system members (not shown in FIG. 1) which areconfigured to receive and process representational information relativefor example to operational settings of the rail vehicle, by a firstelectrical and/or pneumatic and/or manual type channel, denoted 50 inFIG. 1.

These system members are furthermore configured to receive and processrepresentational information relative to parameters of use of the railvehicle, by a second channel of electrical and/or pneumatic and/ormanual type, which is denoted 60 in FIG. 1.

These system members may for example be formed by pneumatic relaysand/or solenoids and/or pressure switches and/or sensors and/or pressurereducing valves and/or electrical relays and/or electronic cards and/orcentral processing units or microprocessors, and/or random access memorycomponents comprising registers adapted to record variables of theparameters created and modified during the execution of programs, and/orcommunication interfaces configured to send and receive data, and/orinternal storage members, such as hard disks, able in particular tostore the executable code of programs enabling the management of theservice and parking brakes 6 and 7.

The control and actuation unit 3 is associated here with a brakinglinkage and with a single brake 5 of the rail vehicle.

As a variant, such a control and actuation unit may be associated withan axle (not shown) of the rail vehicle, provided with a plurality ofbrakes 5, or with a bogie (not shown) of the rail vehicle, provided withtwo axles, or for instance with a wagon (not shown) of the rail vehicle,provided with two bogies, or it is possible for the rail vehicle tocomprise only a single such control and actuation unit.

FIG. 2 diagrammatically represents the conveyance network of pneumaticpipes and the control and actuation unit 3.

The main pipe 70 forms the channel for conveyance of a pneumatic agentdistributed in the conveyance network of pneumatic pipes.

The agent in this main pipe 70 may for example be at a pressure value ofapproximately 9 bars.

The network may comprise what is referred to as a general pipe (notshown), distinct from the main pipe 70, and generally extending inparallel thereto.

The general pipe may enable pneumatic continuity to be ensured along therail vehicle and may authorize the service braking of the vehicle, bydirectly using the fluid passing through the general pipe.

As regards the main pipe 70, this may enable equipment particularly forexample of the rail vehicle braking system to be supplied, and inparticular the source of supply of pneumatic pressure agents 73 hereformed by what is referred to as an auxiliary reservoir.

This network may comprise a filling and distribution pipe 74 which maybe tapped onto (that is to say directly connected to) the main pipe 70,and/or a service brake pipe 75 connected by a tapping 81 onto thefilling and distribution pipe 74, and/or an emergency brake pipe 76tapped onto the service brake pipe 75 by a tapping 82, and/or a controlpipe 78 connected by a tapping 83 onto the filling and distribution pipe74.

The control pipe 78 may be subdivided into two pipes at the location ofa branch tapping 84, respectively to form the parking brake pipe 71directly communicating with the parking brake pressure chamber 25 andinto an oversupply pipe, referred to hereinafter as preset pipe 79 orparking brake pipe or for instance parking brake setting pipe.

Each service brake pipe 75 and/or emergency brake pipe 76 and/or presetpipe 79 may join the brake pipe 72 which directly communicates with theservice brake pressure chamber 13.

The filling and distribution pipe 74 may have a first filling sectionextending between the tapping (not shown) onto the main pipe 70 and theauxiliary reservoir 73, as well as a second distribution sectionextending from a tapping 80 onto the first section.

The control and actuation unit 3 may comprise a one-way valve 85disposed on the first section of the filling and distribution pipe 74near the tapping of the latter onto the main pipe 70, and possibly anisolation tap 86 also disposed on that first section.

The non-return valve 85 may enable the filling of the auxiliaryreservoir 73 by the pneumatic pressure agent coming from the main pipe70 and prohibit the venting of the reservoir 73 into the main pipe 70 ifthe pressure in the latter becomes less than that in the auxiliaryreservoir 73.

The control and actuation unit 3 may comprise a relay device 93, orpneumatic relay, supplied by the second distribution section of thefilling and distribution pipe 74 and connected to the brake pipe 72.

This relay device 93 may be configured to generate, from that seconddistribution section and from template values of pressure, a pressure ofuse at a determined throughput for the filling of the service brakepressure chamber 13.

These template values of pressure may correspond to service brake andemergency brake pressure settings and preset, respectively coming fromthe service brake pipe 75, the emergency brake pipe 76 and from thepreset pipe 79.

The control and actuation unit 3 may comprise, on the service brake pipe75, a pressure reducing valve 87 configured to limit the pressure valuefor example here to approximately 4 bars as well as a distributiondevice 88 formed for example by a monostable solenoid valve andconfigured to receive a control signal corresponding to a service brakesetting CFS.

When the setting value CFS is null, the distribution device 88 may beconfigured to interrupt the service brake pipe 75; and when the settingvalue CFS is not null, the device 88 may be configured to authorize thepassage of a pneumatic pressure agent, called first pressure agent, tothe relay device 93 which receives a service brake pressure templatevalue, and which generates a service brake pressure to supply theservice brake pressure chamber 13 for the braking of the vehicle.

The control and actuation unit 3 may comprise a pressure sensor 90connected to a tapping 89 onto the service brake pipe 75 and which makesit possible to control the service brake pressure template value.

The control and actuation unit 3 may comprise a venting solenoid valve91 connected by the tapping 89 onto the service brake pipe 75 and whichmakes it possible to vent that pipe via a venting aperture 92 on thatsolenoid valve 91.

The solenoid valve 91 may be monostable and be configured for receivinga control signal corresponding to a work setting CT and for operating inreverse.

When the setting value CT is not null, the solenoid valve 91 may beconfigured to interrupt the communication of the service brake pipe 75with the venting aperture 92; and when the setting value CT is null,that solenoid valve 91 may be configured to allow the communication ofthat pipe 75 with that venting aperture 92.

The control and actuation unit 3 may comprise, on the emergency brakepipe 76, a distribution device 96 formed here by a monostable solenoidvalve operating in reverse and configured to receive a control signalcorresponding to an emergency brake setting CFU.

When the setting value CFU is not null, the distribution device 96 maybe configured to interrupt the emergency brake pipe 76; and when thesetting value CFU is null, the device 96 may be configured to authorizethe passage of a pneumatic pressure agent to the relay device 93 whichreceives an emergency brake pressure template value and which generatesan emergency brake pressure to supply the service brake pressure chamber13 for the emergency braking of the vehicle.

The control and actuation unit 3 may comprise a pressure limiter 95 (orpressure reducing valve) on the emergency brake pipe 76 upstream of thedistribution device 96, which limiter 95 may be controlled according toa load parameter param_C of the vehicle received via a load pipe 77connected to the limiter 95; and a pressure sensor 94 which may betapped onto the load pipe 77.

The load parameter param_C is an information item representing thevehicle load and may for example concern a single wagon, or severalsuccessive wagons or the entirety of the rail vehicle.

It will furthermore be noted that certain parameters of operation ofcertain rail vehicles may naturally (or initially) be dependent on thevehicle load for example to manage the service brake whereas others arenot dependent on the vehicle load.

The control and actuation unit 3 may comprise on the brake pipe 72, apressure switch 97 downstream of the relay device 93 and configured tocheck whether or not a pneumatic pressure agent, has a pressure value atleast greater than a predetermined threshold value, in the brake pipe 72and therefore whether there is a pressure in the service brake pressurechamber 13.

The control and actuation unit 3 may comprise on the brake pipe 72 ananti-wheel-slide device 98 here formed by a monostable solenoid valveand configured to receive control signals which correspond toanti-wheel-slide parameters Param_AE of the vehicle; so as to ensure theeffectiveness of the rail vehicle braking.

These anti-wheel-slide parameters Param_AE are information itemsrepresenting the anti-wheel-slide or the wheel-slide of the vehicle andmay for example correspond to the load of the vehicle, to its speed oflocomotion as well as to the service and/or emergency brake templatevalues.

The control and actuation unit 3 may comprise on its control pipe 78 apressure reducing valve 99 configured to limit the pressure value forexample here to approximately 6 bars.

The control and actuation unit 3 may comprise one or more pneumaticdistribution devices 51 dedicated to the parking brake pipe 71 and tothe preset pipe 79.

The pneumatic distribution device or devices 51 may be formed forexample by monostable distributors, also called solenoid valves,connected to the control pipe 78 and/or the brake pipe 72 via the presetpipe 79 and/or the relay device 93, and/or the parking brake pipe 71.

The pneumatic distribution device or devices 51 may be controlled via acontrol line 46 configured to distribute a setting for application ofthe parking brake CFP.

When the parking brake application setting CFP is null, this may meanthat the parking brake 7 must be applied. In this case this is referredto as a security application.

If required, the pneumatic distribution device or devices 51 may beconfigured to disconnect the parking brake pressure chamber 25 from theauxiliary reservoir 73.

The parking brake pressure chamber 25 can then be vented and theblocking finger 20 can come to immobilize the rod 21 of the piston 8.The parking brake is applied. It is in what is referred to as an engagedstate.

At the same time, the pneumatic distribution device or devices 51 may beconfigured to connect the service brake pressure chamber 13 via thebrake pipe 72 to the auxiliary reservoir 73 via the control pipe 78 andthe supply and distribution pipe 74.

Authorization may thus be given to the passage of a pneumatic pressureagent, referred to as third pressure agent, to the relay device 93 whichreceives a pressure preset template value and which generates a pressurepreset to supply the service brake pressure chamber 13 if required.

To release application of the parking brake 7, a non-null setting forapplication of the parking brake CFP may be conveyed in the control line46.

If required, the pneumatic distribution device or devices 51 may beconfigured to connect the parking brake pressure chamber 25 via theparking brake pipe 71 to the auxiliary reservoir 73 via the control pipe78 and the supply and distribution pipe 74.

Authorization may thus be given for the passage of a pneumatic pressureagent, referred to as second pressure agent, directly to the parkingbrake pressure chamber 25 via the parking brake pipe 71. The blockingfinger 20 is then withdrawn into that chamber and releases the rod 21 ofthe piston 8.

At the same time, the pneumatic distribution device or devices 51 may beconfigured to disconnect the service brake pressure chamber 13 from theauxiliary reservoir 73.

The passage of the third pneumatic pressure agent to the relay device 93may thus be prohibited and the latter thus does not receive a pressurepreset template value and vents the pressure preset if required.

The parking brake is then not applied. It is in what is referred to as adisengaged state.

The control and actuation unit 3 comprises an indicator device 100configured to detect and indicate what the state is of the parking brake7 and/or of the service brake 6.

The indicator device 100 indicating what the state is of the parkingbrake 7 and/or of the service brake 6 is configured to receive an itemof information representing the venting and/or the supply of the parkingbrake pressure chamber 25, via a first state pipe 52 which is connectedto the unlocking part 29 for unlocking the parking brake 7.

The indicator device 100 configured to receive an item of informationrepresenting the supply of the service brake pressure chamber 13 by thethird pneumatic pressure agent, via a second state pipe 53 which isconnected to the preset pipe 79.

The indicator device 100 configured to receive an item of informationrepresenting the supply of the service brake pressure chamber 13 by thefirst pneumatic pressure agent, via a third state pipe 54 which isconnected to the service brake pipe 75.

This indicator device 100 may be configured to retrieve these items ofinformation for example directly from the parking brake pipe 71 and/orfrom the preset pipe 79 and/or from the service brake pipe 75.

FIG. 3 shows in more detail the indicator device 100 indicating what thestate is of the parking brake 7 and/or of the service brake 6.

The indicator device 100 is provided with a first switching system 56provided for indicating the state of the parking brake 7.

The first switching system 56 may comprise a first parking contactordevice 55 mechanically connected to the unlocking part 29, a secondparking contactor device 57 which is connected via the first state pipe52 to the first parking contactor device 55, a third parking contactordevice 58 and a fourth parking contactor device 59 which are eachconnected via the second state pipe 53 to the preset pipe 79.

The second parking contactor device 57 may be electrically supplied viaan electrical source 60.

The third and fourth respective parking contactor devices 58 and 59 arefurthermore respectively connected to the second parking contactordevice 57 and to respective visual parking indication devices 61 and 62.

The third and fourth respective parking contactor devices 58 and 59 mayfor example be formed by pressure switches or sensors.

The indicator device 100 is provided with a second switching system 64provided for indicating the state of the parking brake 6.

The second switching system 64 may comprise a first service contactordevice 65 which is connected to the first supply pipe 72, a secondservice contactor device 66 which is connected via the third state pipe54 to the service brake pipe 75, a third service contactor device 67connected via the second state pipe 53 to the preset pipe 79, and afourth service contactor device 68 connected via the second state pipe53 to the preset pipe 79.

The first and second service contactor devices 65 and 66 may beelectrically supplied via a respective electrical source 171, 172.

The third and fourth respective parking contactor devices 67 and 68 arefurthermore respectively connected to the second parking contactordevice 65 and 66, and to respective visual parking indication devices 69and 19.

The first, second, third and fourth service contactor devices 65, 66, 67and 68 may for example be formed by pressure switches or sensors.

With reference to FIGS. 4 to 7 a description will be given of theoperation of the first switching system 56 provided to indicate thestate of the parking brake 7, denoted IFP in FIG. 4.

The IFP information may for example result in a red indicator lightgenerated by the visual parking indication device 62 when the parkingbrake 7 is in the engaged state; whereas it may for example result in agreen indicator light generated by the visual parking indication device61 when the parking brake 7 is in the disengaged state.

In particular, when the second parking contactor device 57 receives anitem of information from the first state pipe 52 according to which theunlocking part 29 is in an unlocking position and the fourth parkingcontactor device 59 receives an item of information from the secondstate pipe 53 according to which there is a preset setting in the presetpipe 79 corresponding to a setting for application of the parking brake7, this means that the parking brake 7 is in the engaged state and thevisual parking indication device 62 is then on.

Conversely, if the second parking contactor device 57 receives an itemof information from the first state pipe 52 according to which theunlocking part 29 is in an unlocking position, and the third parkingcontactor device 58 receives an item of information from the secondstate pipe 53 according to which there is no preset setting in thepreset pipe 79 corresponding to a setting for application of the parkingbrake 7, this means that the parking brake 7 is in the disengaged stateand the visual parking indication device 61 is then on.

The third and fourth respective parking contactor devices 58 and 59 mayfor example be actuated according to a predetermined threshold of thepressure preset value, or of the pressure preset template value.

FIGS. 5 to 7 show very diagrammatically what are the conditions of useof the parking brake 7 and/or of the service brake 6 in which the firstparking contactor device 55 sends an item of information relating to theposition of the unlocking part 29 to the second parking contactor device57 via the first state pipe 52.

In FIG. 5, the first supply pipe 72 does not supply the pressure chamberof the service brake 6 and the second supply pipe 71 supplies thepressure chamber of the parking brake 7; such that the parking brake 7is in the disengaged state. The unlocking part 29 is in an unlockingposition and the first parking contactor device 55 sends the informationto the second parking contactor device 57.

In FIG. 6, the first supply pipe 72 supplies the pressure chamber of theservice brake 6 and the second supply pipe 71 does not supply thepressure chamber of the parking brake 7; such that the parking brake 7is in the engaged state. The unlocking part 29 is in a locking positionand the first parking contactor device 55 sends the information to thesecond parking contactor device 57.

In FIG. 7, the first supply pipe 72 does not supply the pressure chamberof the service brake 6 and the second supply pipe 71 does not supply thepressure chamber of the parking brake 7; such that the parking brake 7is in the disengaged state. The unlocking part 29 is in an unlockingposition after having been manually shifted, and the first parkingcontactor device 55 sends the information to the second parkingcontactor device 57.

As explained above, the information sent by the first parking contactordevice 55 to the second parking contactor device 57 via the first statepipe 52 is processed in combination with the information representingthe preset setting in the preset pipe 79 for the purpose of indicatingwhether the parking brake 7 is in the engaged state or in the disengagedstate.

With reference to FIG. 8 the operation will now be described of theswitching system 64 provided to indicate the state of the service brake6, denoted IFS.

The IFS information may for example result in a red indicator lightgenerated by the visual service indication device 19 when the servicebrake 6 is in the engaged state; whereas it may for example result in agreen indicator light generated by the visual service indication device69 when the service brake 6 is in the disengaged state.

In particular, when the first service contactor device 65 receives anitem of information from the first supply pipe 72 according to which thelatter supplies the service brake pressure chamber 6 and when the fourthservice contactor device 68 receives an item of information from thesecond state pipe 53 according to which there is no preset setting inthe preset pipe 79, this means that the service brake 6 is in theengaged state and the visual service indication device 19 is then turnedon.

Moreover, if the second service contactor device 66 receives an item ofinformation from the third state pipe 54 according to which there is aservice brake setting in the service brake pipe 75 and if the fourthservice contactor device 68 receives an item of information from thesecond state pipe 53 according to which there is a preset setting in thepreset pipe 79 corresponding to a setting for application of the parkingbrake 7, this means that the service brake 6 is in the engaged state andthe visual service indication device 19 is then on.

Conversely, when the first service contactor device 65 receives an itemof information from the first supply pipe 72 according to which thelatter does not supply the service brake pressure chamber 6 and when thethird service contactor device 67 receives an item of information fromthe second state pipe 53 according to which there is no preset settingin the preset pipe 79, this means that the service brake 6 is in thedisengaged state and the visual service indication device 69 is thenturned on.

Moreover, if the second service contactor device 66 receives an item ofinformation from the third state pipe 54 according to which there is noservice brake setting in the service brake pipe 75 and if the thirdservice contactor device 67 receives an item of information from thesecond state pipe 53 according to which there is a preset setting in thepreset pipe 79 corresponding to a setting for application of the parkingbrake 7, this means that the service brake 6 is in the disengaged stateand the visual service indication device 69 is then on.

The first service contactor device 65 may for example be actuatedaccording to a predetermined threshold of service brake pressure value,the second service contactor device 66 may for example be actuatedaccording to a predetermined threshold of service brake pressuretemplate value, and the third and fourth respective service contactordevices 67 and 68 may for example be actuated according to apredetermined threshold of pressure preset value, or of pressure presettemplate value.

FIG. 9 illustrates a first variant embodiment of the second switchingsystem 64 provided to indicate the state of the service brake 6, denotedIFS.

The first and second service contactor devices 65 and 66 are mountedhere in series, rather than in parallel, and the third and fourthservice contactor devices 67 and 68 are eliminated.

When the first service contactor device 65 receives an item ofinformation from the first supply pipe 72 according to which the lattersupplies the service brake pressure chamber 6 and when the secondservice contactor device 66 receives an item of information from thethird state pipe 54 according to which there is a service brake settingin the service brake pipe 78, this means that the service brake 6 is inthe engaged state and the visual service indication device 19 is thenturned on.

Conversely, if the first service contactor device 65 receives an item ofinformation from the first supply pipe 72 according to which the latterdoes not supply the pressure chamber of the service brake 6, this meansthat the service brake 6 is in the disengaged state and the visualservice indication device 69 is then turned on.

Furthermore, when the first service contactor device 65 receives an itemof information from the first supply pipe 72 according to which thelatter supplies the service brake pressure chamber 6 and when the secondservice contactor device 66 receives an item of information from thethird state pipe 54 according to which there is no service brake settingin the service brake pipe 79, this means that the service brake 6 shouldbe in the disengaged state and the visual service indication device 69is then turned on. However, this variant embodiment does not enable apossible service brake control failure to be intercepted.

FIG. 10 illustrates a second variant embodiment of the second switchingsystem 64 provided to indicate the state of the service brake 6, denotedIFS. This second variant differs from the embodiment illustrated in FIG.8 in that it is what is referred to as a series arrangement rather thanparallel. Furthermore, contrary to the first variant illustrated in FIG.9 which does not take into account the preset setting, the secondvariant takes into account the preset setting like the embodimentillustrated in FIG. 8.

In particular, in FIG. 10, the third service contactor device 67 isinterposed between the first and second service contactor devices 65 and66.

When the first service contactor device 65 receives an item ofinformation from the first supply pipe 72 according to which the lattersupplies the service brake pressure chamber 6, when the third servicecontactor device 67 receives an item of information from the secondstate pipe 53 according to which there is a preset setting in the presetpipe 79 constituting a setting for application of the parking brake 7,and when the second service contactor device 66 receives an item ofinformation from the third state pipe 54 according to which there is aservice brake setting in the service brake pipe 78, this means that theservice brake 6 is in the engaged state and the service visualindication device 19 is turned on.

Moreover, if the first service contactor device 65 receives an item ofinformation from the first supply pipe 72 according to which the lattersupplies the service brake pressure chamber 6 and if the third servicecontactor device 67 receives an item of information from the secondstate pipe 53 according to which there is no preset setting in thepreset pipe 79, this means that the service brake 6 is in the engagedstate and the visual service indication device 19 is then turned on.

Conversely, when the first service contactor device 65 receives an itemof information from the first supply pipe 72 according to which thelatter supplies the service brake pressure chamber 6, when the thirdservice contactor device 67 receives an item of information from thesecond state pipe 53 according to which there is a preset setting in thepreset pipe 79 constituting a setting for application of the parkingbrake 7, and when the second service contactor device 66 receives anitem of information from the third state pipe 54 according to whichthere is no service brake setting in the service brake pipe 78, thismeans that the service brake 6 is in the disengaged state and theservice visual indication device 69 is turned on.

Moreover, if the first service contactor device 65 receives an item ofinformation from the first supply pipe 72 according to which the latterdoes not supply the pressure chamber of the service brake 6, this meansthat the service brake 6 is in the disengaged state and the visualservice indication device 69 is then turned on.

FIG. 11 illustrates a third variant embodiment of the second switchingsystem 64 provided to indicate the state of the service brake 6, denotedIFS.

The second and third service contactor devices 66 and 67 are pneumaticthreshold valves which are supplied directly via the first supply pipe72. The first and fourth service contactor devices are eliminated.

In particular, when the first supply pipe 72 supplies the service brakepressure chamber 6 and when the third service contactor device 67receives an item of information from the second state pipe 53 accordingto which there is no preset setting in the preset pipe 79, this meansthat the service brake 6 is in the engaged state such that the visualservice indication device 19 is then turned on.

Moreover, when the first supply pipe 72 supplies the service brakepressure chamber 6, when the third service contactor device 67 receivesan item of information from the second state pipe 53 according to whichthere is a preset setting in the preset pipe 79 constituting a settingfor application of the parking brake 7, and when the second servicecontactor device 66 receives an item of information from the third statepipe 54 according to which there is a service brake setting in theservice brake pipe 78, this means that the service brake 6 is in theengaged state and the service visual indication device 19 is then turnedon.

Conversely, when the first supply pipe 72 does not supply the pressurechamber of the service brake 6, or else when the first supply pipe 72supplies the service brake pressure chamber 6, when the third contactordevice 67 receives an item of information from the second state pipe 53according to which there is a preset setting in the preset pipe 79constituting a setting for application of the parking brake 7, and whenthe second service contactor device 66 receives an item of informationfrom the third state pipe 54 according to which there is no servicebrake setting in the service brake pipe 78, this means that the servicebrake 6 is in the disengaged state and the visual service indicationdevice 69 is then visible.

In a variant not illustrated, the rail vehicle braking system is not ofthe same kind as that described with reference to FIG. 1, but rather arail vehicle braking system with a parking brake having a spring, of thetype described in European patent application EP 2 154 040.

In such a rail vehicle braking system with a parking brake having aspring, the present invention gives the possibility of providing aparking brake indicator device which is provided to indicate the engagedor disengaged state of the latter.

The information relating to the state of the parking brake may forexample result in a red indicator light generated by a visual parkingindication device when the parking brake is in the engaged state;whereas it may for example result in a green indicator light generatedby another visual parking indication device when the parking brake is inthe disengaged state.

In particular, the parking brake indicator device may comprise a firstparking contactor device mechanically connected to an unlocking part ofthe same type as that described above and provided to pass the parkingbrake from its engaged state to its disengaged state.

The parking brake indicator device may further comprise a second parkingcontactor device which is connected via a first state pipe to the firstparking contactor device.

The parking brake indicator device may also comprise a third contactordevice connected to another state pipe itself connected either to asupply pipe of the parking brake, or to a setting pipe of the parkingbrake.

The second and the third parking contactor devices may be electricallysupplied via a respective electrical source.

When the second parking contactor device receives an item of informationfrom the state pipe according to which the unlocking part is in alocking position and the third parking contactor device receives an itemof information from the other state pipe according to which there is aparking brake setting and/or when the parking brake pressure chamber ofthe system is not supplied, corresponding to a setting for applicationof the parking brake, this means that the parking brake is in theengaged state and one of the visual parking indication devices is thenturned on.

When the second parking contactor device receives an item of informationfrom the state pipe according to which the unlocking part is in anunlocking position, this means that the parking brake is in thedisengaged state and the other of the visual parking indication devicesis then turned on, whatever the item of information received by thethird parking contactor device or device.

More generally, the invention is not limited to the examples describedand illustrated.

1. A rail vehicle braking system comprising: a body delimiting one orboth of a service brake pressure chamber or a parking brake pressurechamber; a parking brake movable relative to the body; an unlocking partfor unlocking the parking brake connected to the parking brake pressurechamber and accessible from outside the body; and a parking brakeindicator device, wherein the indicator device is configured to receivea first item of information representing a position of the unlockingpart via a first state pipe configured to be connected to the unlockingpart, the indicator device also configured to receive at least onesecond item of information representing one or more of supply or ventingof one or more of a service brake pressure chamber or the parking brakepressure chamber, the indicator device configured to receive the atleast one second item of information via at least one of a second statepipe or a third state pipe configured to be connected to one or more ofa service brake pipe or to a parking brake, the first item ofinformation being processed in combination with the at least one seconditem of information to detect and indicate an engaged state or adisengaged state of the parking brake.
 2. The rail vehicle brakingsystem according to claim 1, wherein the indicator device is configuredto receive a third item of information representing the supply of theservice brake pressure chamber by a pneumatic pressure agent, theindicator device configured to receive the third item of information viathe second state pipe which is configured to be connected to a parkingbrake setting pipe, the indicator device configured to receive a fourthitem of information representing the supply of the service brakepressure chamber by another pneumatic pressure agent, the indicatordevice configured to receive the fourth item of information via thethird state pipe which is configured to be connected to a service brakepipe.
 3. The rail vehicle braking system according to claim 1, whereinthe unlocking part is coupled to a switch of the indicator device, theindicator device mechanically connected to the unlocking part, theunlocking part having a first position and a second position.
 4. Therail vehicle braking system according to claim 1, wherein the indicatordevice comprises a first parking contactor device mechanically connectedthe unlocking part, a second parking contactor device which is connectedto the first parking contactor device via the first state pipe, a thirdparking contactor device, and a fourth parking contactor device whichare each connected via the second state pipe to a parking brake settingpipe, the respective third and fourth parking contactor devices beingrespectively connected to the second parking contactor device and torespective visual parking indication devices of the indicator device. 5.The rail vehicle braking system according to claim 4, wherein one ormore of: (a) the second parking contactor device is electricallysupplied via an electrical source or (b) the third and fourth respectiveparking contactor devices are formed by pressure switches or sensors. 6.The rail vehicle braking system according to claim 4, wherein, when thesecond parking contactor device receives the first item of informationfrom the first state pipe according to which the unlocking part is in anunlocking position and the fourth parking contactor device receives thesecond item of information from the second state pipe according to whichthere is a parking brake setting in the parking brake pipe correspondingto a setting for application of the parking brake, the parking brake isin an engaged state and the visual parking indication device is on. 7.The rail vehicle braking system according to claim 4, wherein, when thesecond parking contactor device receives the first item of informationfrom the first state pipe according to which the unlocking part is in anunlocking position and the third parking contactor device receives thesecond item of information from the second state pipe according to whichthe parking brake setting has a null value in the parking brake pipe,the parking brake is in a disengaged state and the visual parkingindication device is on.
 8. The rail vehicle braking system according toclaim 1, wherein the indicator device comprises a first parkingcontactor device mechanically connected to the unlocking part, a secondparking contactor device connected to the first parking contactor devicevia the first state pipe, and a third contactor device connected toanother state pipe that is joined either to a supply pipe of the parkingbrake; or to a setting pipe of the parking brake.
 9. The rail vehiclebraking system according to claim 8, wherein, when one or more of: (a)the second parking contactor device receives the first item ofinformation from the first state pipe according to which the unlockingpart is in a locking position and the third contactor device receivesthe second item of information from the second state pipe according towhich there is a parking brake setting or (b) when the parking brakepressure chamber of the system is not supplied, corresponding to asetting for application of the parking brake, the parking brake is inthe engaged state and a visual parking indication device is turned on.10. The rail vehicle braking system according to claim 8, wherein, whenthe second parking contactor device receives the first item ofinformation from the first state pipe according to which the unlockingpart is in an unlocking position, the parking brake is in the disengagedstate and a visual parking indication device is turned on, regardless ofthe second item of information received by a third parking contactordevice.
 11. A rail vehicle having brakes with at least one lining orwith at least one block, comprising at least one of the rail vehiclebraking system according to claim 1, which is configured to act on theat least one lining or on the at least one block of the rail vehicle.12. A braking system comprising: a parking brake including an unlockingpart configured to unlock the parking brake; a parking brake indicatordevice configured to receive positions of the unlocking part via a firststate pipe, the indicator device configured to receive a firstindication of one or more of supply or venting of a brake pressurechamber via a second state pipe; and a control and actuation unitconfigured to detect and indicate an engaged state or a disengaged stateof the parking brake based on at least one of the positions received viathe first state pipe and the first indication of the one or more of thesupply or the venting of the brake pressure chamber.
 13. The brakingsystem of claim 12, wherein the indicator device is configured toreceive a second indication representative of the supply of the brakepressure chamber, the control and actuation unit configured to detectand indicate the engaged state or the disengaged state of the parkingbrake based on at least one of the positions received via the firststate pipe, the first indication, and the second indication.
 14. Thebraking system of claim 12, wherein the indicator device comprises afirst contactor device configured to be connected with the unlockingpart of the parking brake, a second contactor device configured to beconnected with the first contactor device via the first state pipe, athird contactor device configured to be connected to a parking brakesetting pipe, and a fourth parking contactor device configured to beconnected to the parking brake setting pipe, the third and fourthcontactor devices connected to the second contactor device and to visualparking indication devices of the indicator device.
 15. The brakingsystem of claim 14, wherein the second contactor device is electricallysupplied via an electrical source and the third and fourth contactordevices are formed by pressure switches or sensors.
 16. The brakingsystem of claim 12, wherein the control and actuation unit is configuredto determine that the parking brake is in an engaged state and toactivate a visual indication device responsive to the unlocking partbeing in an unlocking position of the positions and the first indicationof the one or more of the supply or the venting of the brake pressurechamber.
 17. The braking system of claim 12, wherein the control andactuation unit is configured to determine that the parking brake is in adisengaged state and to activate a visual indication device responsiveto the unlocking part being in an unlocking position of the positionsand the first indication representing the venting of the brake pressurechamber.
 18. The braking system of claim 12, wherein the control andactuation unit is configured to determine that the parking brake is inan engaged state and to activate a visual indication device responsiveto the unlocking part being in an unlocking position of the positionsand receiving the first indication of the supply of the brake pressurechamber, and the control and actuation unit is configured to determinethat the parking brake is in a disengaged state and to activate thevisual indication device responsive to the unlocking part being in theunlocking position of the positions and receiving the first indicationof the venting of the brake pressure chamber.
 19. The braking system ofclaim 12, wherein the control and actuation unit is configured todetermine that the parking brake is in an engaged state and to activatea visual indication device responsive to the unlocking part being in alocking position of the positions and receiving the first indication ofa parking brake setting.
 20. The braking system according to claim 19,wherein the visual indication device is a first visual indicationdevice, and the control and actuation unit is configured to determinethat the parking brake is in a disengaged state and to activate a secondvisual indication device responsive to the unlocking part being in anunlocking position regardless of the first indication.